Belgium research has a longstanding tradition and strong track record in organellar research. Christian de Duve, a Belgian cell biologist, discovered two cellular organelles (lysosomes and peroxisomes), for which he shared the Nobel Prize in Physiology or Medicine in 1974 with Albert Claude (Belgian) and George Palade (Romania). Having worked at the border of biochemistry and cell biology, de Duve insisted on the importance of collaborative work and highly valued interdisciplinary research. Hundred years after his day of birth, four Belgian labs have teamed up with an American lab to form the ReACTs consortium. We will tackle the organellar communication within the plant cell. We focus on thiol-based redox-sensing proteins within signaling circuits between plant organelles (chloroplasts and mitochondria) and the nucleus. For this project, we take a bold ab initio approach without constraints in order to discover new important cysteine sites on proteins, not only focusing on specific transcription factors, but by building on the technology that was developed within the ReACTs consortium. By going beyond our paved landscaping paths and by combining new trapping and interaction technologies with structural and functional studies, we will not only pinpoint, but also scrutinize the kinetic privilege of cysteine sites as stress sensors.